Series telephone system.



(In. Model) 0. A. CASPEBKE.

SERIES TELEPHONE SYSTEM. (Amalie-flea and Apr- 11, 1901.)

Patented Sept. 3, 19m.

Inventor 1m: Nonms PETERS co. Puoroumnjvusnmommp. c.

telephone-lines are at present operated.

PATENT EErcE.

CHARLES A. OASPERKE, OF BRANDENBURG, KENTUCKY.

SERIES TELEPHONE SYSTEM.

SPECIFICATION forming part of Letters Patent No. 682,030, dated September 3, 1901.

Application filed April 17, 1901.

To all whom it may concern:

Be it known that I, CHARLES A. OASPERKE, a citizen of the United States, residing at Brandenburg, in the county of Meade and State of Kentucky, have invented new and useful Improvements in Series Telephone Systems, of which the following is a specification.

My invention is concerned with series telephone systems, and has for its object to provide means for overcoming the impedance to to the voice-currents on series telephoneline's and for rendering the ringer more efiicient without materially changing the apparatus used. The impedance of the ringercoils on a series telephone-circuit not only decreases the intensity of the vibrations of the undulatory voice currents, but also changes somewhat the form of the vibrations of these currents. Itis therefore impossible to transmit the voice-currents over long series lines crowded with stations. By my invention I provide means at each station for overcoming the local impedance thereof and for correcting the distorted vibrations in the voice currents passing therethrough, the same consisting of a shunt-circuit bridged across the ringer-coils and including a con-. denser of proper capacity. This decreases the resistance to the alternating signalingcurrent, increases the efficiency of the ringer, and also provides another path for the voicecurrents other than through the ringer-coils alone. The result is that the impedance of each station is decreased, and as the induced current of the condenser has an opposite effect in phase to the effect of the self-induction of the ringer-coils the distortion of either ringer or condenser is counterbalanced. A double efiect is thereby produced, which overcomes the disadvantages under which series In the accompanying drawing my invention is illustrated by a diagrammatic view showing two substations of a series telephoneline.

The substations A and B have the line- Wires 1, 2, and 3 leading into and from the same, the line including in series the ringercoils 4 and 5 of the respective stations. Bridged across the ringer-coils 4 is a concreases the output of the generator.

denser 6 in a shunt-circuit 7, and bridged Serial No. 56,258. (No model.)

across the ringer-coils 5 is a condenser 8 in a shunt-circuit 9. The coils 4 and 5 and the condensers 6 and 8 may be of any suitable or it is received at such station by repeating it at every such station, thus practically dividing the entire talking-circuit into short sections, each repeating to the next adjacent one and in effect leaving the ringer-coils 4 5 out of the way when the condenser used is of proper capacity to receive the vibrations produced by the voice. Being so rapid and inten'se these Vibrations are absorbed by one set of plates of a very small capacity condenser and repeated by induction to the opposite plates. The voice at the receiving-station is made more natural, and the change in the form of the voice-currents ordinarily produced by the substations is prevented by 10- cating the condenser at the point of the trouble on a series circuit. Furthermore, the efficiency of the line in both talking and ringing is increased, as the charging of the condensers along the line practically reduces the resistance of the line, and therefore in- The condenser at each station acts as a local storage-cell, and being of small capacity it robs the current of sufficient supply to charge itself; but this is done with the effect of decreasingthe resistance from the generator until the condenser is charged to a capacity somewhat in excess of the capacity in normal intensity of the generator impulse, as it meets with its highest charge at first while the current is overcoming the self-induction in the ringer-coils. As soon as this self-induction is overcome the excess of charge is added to the flow from the generator as the intensity decreases, and a similar effect is produced when the current becomes of opposite polarity. This takes place from the side receiving current from the generator, and a similar assistance to the efficiency of the ringer acts on the opposite plates in complement with that already mentioned, and so on at each station on the line. The result of the foregoing is that the ringing pulsations are slightly prolonged during the time of greatest potential and at the same time are made practically sinusoidal in phase. Furthermore, practically the total amount of the increased current output of the generator is utilized. It will thus be seen that by my invention the inductive resistance and in effect ohmic resistance to vibrating currents at each intermediate station is reduced, making the ringing as well as the talking more efficient.

At substations where the receiver 10 is apt to be removed often for any cause when said station is neither calling nor beingcalled it is important to connect the shunt-circuit containing the condenser with the line at a point above the hook-switch 11, on which the receiver is suspended, and to locate in said shunt-circuit adjacent to the hook-switch 11 a switch 12, by means of which the shunt circuit may be opened when the station is actually engaged in conversation; otherwise the local impedance of the station would not be prevented on account of the shunt being connected to one line only, since in the usual wiring of series telephones the shuntcircuit containing the condenser would not extend to the line entering station A, the receiver and secondary winding of the induction coil would add great impedance to the circuit at said station while the hook-switch 11 is in its upper positionthat is to say, the shunt-circuit should be closed only when the station is not actually engaged in conversation. However, at such stations where the hook-switch is never left in its upper position except during conversation it is sufficient to connect the shunt-circuit to the line below the hook-switch, thereby avoiding the necessity of the switch 12.

Having now described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In a series telephone system, a ringercoil at each station and a condenser in multiple therewith the said condenser being included in a shunt-circuit having no source of impedance therein, as and for the purpose set forth.

2. Ina series telephone system, a ringer coil at each station and a condenser connected with the line and bridged across said coil the said condenser being included in a shunt-circuit having no source of impedance therein, as and for the purpose set forth.

3. In a series telephone system, serially-arranged ringer-coils located respectively-at each station, a non-impeding shunt-circuit around each of said coils, and a condenserin said shunt-circuit, as and for the purpose set forth.

4:. In a series telephone system, a ringercoil at each station, a normally-closed nonimpeding shunt around said coil, connected with the line above the hook-switch for the receiver, a condenser in said shunt, and a switch for openingsaid shunt, as and for the purpose set forth.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

CHARLES A. OASPERKE.

Witnesses:

JOHN BIRCHER, J. MORGAN RICHARDSON. 

